Question: Which is the medical specialty of the field of work of Sigmund Freud?
Paraphrase: Which is the restorative claim to fame of the field of work of Sigmund Freud?
SPARQL (Wikidata):  select distinct ?obj where { wd:Q9215 wdt:P101 ?obj . ?obj wdt:P31 wd:Q930752 } 
Answer: neurology